Door hinge mechanism for telecommunications panel

ABSTRACT

A double jointed hinge mechanism for pivotally coupling a door to a telecommunications chassis includes an first hinge arm configured to be non-rotatably attached to the chassis, a second hinge arm non-rotatably attached to the door, and a third hinge arm pivotally attached to the first and second hinge arms. The hinge mechanism is configured such that the door can be placed in a first open position and a second open position through rotation about first and second rotational axes. In the first open position, the door is in a generally horizontal position and below the first rotational axis. In the second open position, the door is in a generally vertical position and forward of a vertical plane defined by the first rotational axis.

RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/049,189, filed on Sep. 11, 2014, the entirety of which isincorporated by reference herein.

BACKGROUND

As demand for telecommunications increases, fiber optic networks arebeing extended in more and more areas. Management of the cables, ease ofinstallation, and ease of accessibility for later management areimportant concerns. As a result, there is a need for fiber optic deviceswhich address these and other concerns.

SUMMARY

According to an inventive aspect, the present disclosure relates to ahinge mechanism for the door of a telecommunications chassis or panel,wherein the hinge mechanism is configured to allow the door of thechassis to be fully opened, allowing extension or removal of “pull-out”blades or trays installed in the chassis. According to an aspect of thedisclosure, hinge mechanism may be used for a fiber optic chassis,wherein the “pull-out” trays may house fiber optic equipment in the formof fiber optic cassettes. Each cassette may include at least oneconnector that provides a signal entry location and at least oneconnector that provides a signal exit location and a fiber opticalcircuit thereinbetween for relaying the signal from the entry locationto the exit location. The door hinge mechanism allows the trays to befully pulled out of the chassis for access to the connectors of thecassettes.

According to another aspect, the present disclosure relates to atelecommunications system comprising a telecommunications chassis and adoor pivotally attached to the chassis via a hinge mechanism. In oneaspect, the hinge mechanism includes a first hinge arm affixed to thetelecommunications chassis, a second hinge arm affixed to the door, anda third hinge arm. The third hinge arm may include a first extensionportion pivotally attached to the first hinge arm and a second extensionportion pivotally attached to the second hinge arm to provide a doublejointed connection between the door and the chassis. In one example, thefirst extension portion meets the second extension portion at an angleto form a dog-leg shaped hinge arm.

In one embodiment, the hinge mechanism allows the door to be placed inmultiple positions, such as a closed position, a first open position,and a second open position through the rotation of the hinge mechanismabout a first rotational axis and a second rotational axis. In theclosed position, the door is disposed in a generally vertical positionto at least partially cover the open front of the chassis, wherein thedoor is located above a horizontal plane extending through the firstrotational axis and behind a vertical plane extending through the firstrotational axis. In the first open position, the door is disposed in agenerally horizontal position, wherein the door is at least partiallybelow the horizontal plane extending through the first rotational axis.In the second open position, the door is disposed in a generallyvertical position and rotated from the closed position about the firstrotational axis by about 180 degrees, wherein the door is disposedforward of the vertical plane extending through the first rotationalaxis.

A variety of additional inventive aspects will be set forth in thedescription that follows. The inventive aspects can relate to individualfeatures and combinations of features. It is to be understood that boththe foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of the broadinventive concepts upon which the embodiments disclosed herein arebased.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top, front, right side perspective view of a fiber optictelecommunications chassis including a door hinge mechanism havingfeatures that are examples of inventive aspects in accordance with thepresent disclosure, the door of the chassis being in a closed position;

FIG. 2 is a top, front, right side perspective view of the fiber optictelecommunications chassis of FIG. 1, the door of the chassis being in afirst open position;

FIG. 3 is an enlarged view of a portion of the chassis shown in FIG. 2;

FIG. 4 is a top, front, right side perspective view of the fiber optictelecommunications chassis of FIG. 1, the door of the chassis being in afirst open position and with a telecommunications tray shown fullyextended;

FIG. 5 is a side view of the chassis of FIG. 1 in the configurationshown in FIG. 4;

FIG. 6 is a top, front, right side perspective view of the fiber optictelecommunications chassis of FIG. 1, the door of the chassis being in asecond open position;

FIG. 7 is a side view of the chassis of FIG. 1, the door of the chassisbeing in a closed position;

FIG. 8 is a side view of the chassis of FIG. 1, the door of the chassisbeing in an intermediate open position;

FIG. 9 is a side view of the chassis of FIG. 1, the door of the chassisbeing in the first open position;

FIG. 10 is a side view of two of the chassis of FIG. 1 in a stackedconfiguration, the door of the bottom chassis being in the closedposition, the door of the top chassis being shown in both the closedposition and the second open position.

FIG. 11 is a perspective view of a first hinge arm of the door hingemechanism of FIG. 1;

FIG. 12 is a perspective view of a second hinge arm of the door hingemechanism of FIG. 1; and

FIG. 13 is a perspective view of a third hinge arm of the door hingemechanism of FIG. 1.

FIG. 14 is a perspective view of an alternative embodiment of the firsthinge arm of FIG. 11;

DETAILED DESCRIPTION

The present disclosure is directed to an inventive hinge mechanism 10that can be used for a door 12, or a different cover structure, of atelecommunications chassis or panel 14 in a telecommunications system20. The hinge mechanism 10 is configured to allow the door 12 of thechassis 14 to be moved between a fully closed position, as shown inFIGS. 1 and 7, to multiple open positions, as shown in FIGS. 2-6 and8-10. The hinge mechanism 10 enables the door 12 to be openedsufficiently to allow the extension or removal of “pull-out” blades ortrays 16 installed in the chassis 14 without interference from the door12. In one aspect, the hinge mechanism 10 allows the door 12 to beplaced in at least a first open position and a second open position. Inthe first open position, as shown at FIGS. 2-5 and 9, the door 12 can berotated from the closed position and disposed into a generallyhorizontal position that is fully below any extended blades or trays 16of the chassis 14. This position is advantageous where equipment belowthe chassis 14 (e.g. equipment 100 shown in FIG. 9) prevents the door 12from rotating more fully open into the second position. In the secondopen position, as shown in FIGS. 6 and 10, the hinge mechanism 10 allowsthe door 12 to be disposed forward of equipment below the chassis 14(e.g. another chassis 14) such that the door 12 can be placed in agenerally vertical position and below any extended blades or trays 16 ofthe chassis 14.

According to an aspect of the disclosure, the hinge mechanism 10 may beused for a telecommunications chassis 14 in the form of a fiber opticchassis, wherein the “pull-out” trays 16 may house fiber opticequipment. According to one example embodiment, the fiber opticequipment housed by the trays 16 may be in the form of fiber opticcassettes. An example of a fiber optic chassis or panel 14 that includes“pull-out” blades or trays 16 that may utilize the door hinge mechanism10 of the present disclosure is shown in FIGS. 1-10. It should be notedthat although the door hinge mechanism 10 of the present disclosure maybe used on and will be described with respect to the chassis or panel 14described herein, the door hinge mechanism 10 may be utilized on anytelecommunications chassis that may require access to equipment therein.The chassis 14 shown herein is simply an example of a type of chassisthat may utilize the hinge mechanism 10 of the present disclosure.Chassis 14 of this configuration are particularly suitable for the hingemechanism 10 of the present disclosure since they include “pull-out”trays or blades 16 that may need full opening of the doors 12 foraccessing or removing the trays 16.

In one aspect of the disclosure, the telecommunications chassis 14 maybe configured for mounting to a telecommunications rack that may be astandard 19-inch rack. According to the depicted embodiment, eachchassis 14 is defined by a right wall 22, a left wall 24, a rear wall26, and a top wall 28 that extends from the right wall 22 to the leftwall 24. The chassis 14 defines an open front or face 30 that iscloseable by the door 12. As shown, the open front or face 30 extendsalong and/or defines a plane that is generally vertical when the chassis14 is horizontally disposed. The door 12 is mounted to the chassis 14using the inventive hinge mechanism 10 of the present disclosure. Thechassis 14 is configured to house slidable blades 16 (e.g. 16 a, 16 b,16 c) that can be provided with cable management devices 18 (e.g. 18 a,18 b, 18 c) and can be configured to hold fiber optic cassettes. Eachchassis 14 may be configured to occupy a selected height, for exampleone standard rack unit (1RU) or two standard rack units (2RU).

Now referring to FIGS. 11-13 close-up views of the individual componentsof the hinge mechanism 10 are shown. It should be noted that the hingemechanism 10 includes the same configuration at both the right side andthe left side of the chassis 14. For ease of description andillustration, only one side of the hinge mechanism 10 will be discussedin detail with the understanding that the features discussed are fullyapplicable to the other side.

As most easily seen at FIGS. 3, 8-9, and 11-13, the hinge mechanism 10includes a first hinge arm 40, a second hinge arm 50, and a third hingearm 60 that together form a double-jointed connection between the door12 and the chassis 14.

Referring to FIG. 11, the first hinge arm 40 is shown in greater detail.In one aspect, the first hinge arm 40 has a main body 42, extendingalong a longitudinal axis L1, that is configured to be supported by andmounted to the chassis 14. As shown, the first hinge arm 40 is securedto the chassis 14 by one or more fasteners 70 passing through thechassis 14 and extending into a mounting aperture 42 a of the firsthinge arm 40. In one embodiment, the mounting aperture 42 a is threadedand the fastener 70 is a screw that engages with the threads.

The main body 42 can also be provided with a lateral extension member 44that engages with a portion of the chassis 14 so as to retain thedesired longitudinal position of the first hinge arm 40 with respect tothe chassis 14. The lateral extension member 44 also functions to absorbloading from the door 12 that would otherwise be absorbed by thefastener 70 and thus enhances the service life of the fastenerconnection. As shown, the lateral extension member 44 extends in adirection generally orthogonal to the axis L1.

The first hinge arm 40 also includes a longitudinal extension member 46extending away from the main body 42 and generally parallel to axis L1.As shown, the longitudinal extension member 46 provides a supportsurface for a hinge post 48 that extends in a lateral directiontransverse to the longitudinal extension member 46 and axis L1. Thehinge post 48 is spaced from the main body 42 and provides for a pivotalconnection point between the first hinge arm 40 and that third hinge arm60. The third hinge arm 60 is shown as being provided with a radiusedopening 68 through which the hinge post 48 extends. Thus, in theconfiguration shown, the third hinge arm 60 is rotatable with respect tothe first hinge arm 40 about a rotational axis R1 that is coaxial withboth the longitudinal axis of the hinge post 48 and the center of theradiused opening 68.

In one aspect, the hinge post 48 is connected to the longitudinalextension member 46 at a first end 48 a and has a free, second end 48 b.However, it is noted that the first hinge arm 40 could include a secondlongitudinal extension member 46 extending from the main body 42 andconnected to the second end 48 b of the hinge post 48. In such aconfiguration, the third hinge arm 60 could be configured with an openended female portion that could connect to the post member 48 via asnap-fit or other type of connection. In yet another alternativearrangement, and as shown at FIG. 14, the hinge post 48 can be providedwith a hook or retaining portion 49 extending from the second end 48 bof the hinge post 48. As shown, the hook or retaining portion 49 extendsaway from the hinge post 48 in a direction towards the lateral extensionmember 44 and acts to retain the third hinge arm 60 onto the hinge post48. The hook or retaining portion 49 is shaped such that the hook orretaining portion 49 and the hinge post 48 can be passed through theopening 68 by rotating the third hinge arm 60 with respect to the firsthinge arm 40 during installation. Once the first and third hinge arms40, 60 are aligned in an installed position, for example as shown atFIG. 3, the hook or retaining portion 49 will prevent the third hingearm 60 from sliding off of the hinge post 48 of the first hinge arm 40.

Referring to FIG. 12, the second hinge arm 50 is shown in greaterdetail. In one aspect, the second hinge arm 50 has a main body 52,extending along a longitudinal axis L2, that is configured to besupported by and mounted to the door 12. As shown, the second hinge arm50 is secured to the door 12 by one or more fasteners (not shown)passing through the door and extending into mounting apertures 52 a ofthe first hinge arm 40. In one embodiment, the mounting apertures 52 aare threaded and the fasteners are screws that engage with the threads.

The second hinge arm 50 is also shown as being provided with a firstpair of longitudinal extension members 54 extending from the main body52 and generally parallel to axis L2. The extension member 54 supports atransversely (i.e. orthogonal to axis L2) mounted or formed latch post55 that is spaced from the main body 52. The latch post 55 is configuredto releasably engage with a corresponding latch member 80 mounted to thechassis 14. The latch member 80 is most easily viewed at FIGS. 8 and 9.Once engaged, the latch post and latch member 80 cooperate to retain thedoor 12 in the closed position. As shown, the latch member 80 includes arecessed portion 82 having an initial opening defining a smallerdimension than that of the latch post 55 such that a snap-fit typeconnection is achieved between the latch post 55 and the latch member80. As shown, the latch member 80 is mounted to the chassis 14 via afastener 84, such as a screw.

The second hinge arm 50 is also shown as being provided with a secondpair of longitudinal extension members 56 extending away from the mainbody 52 at an end opposite the extension members 54. As shown, a slotopening 56 a is defined between the longitudinal extension members 56that allows for the third hinge arm 60 to be inserted partially into thesecond hinge arm 50.

Each of the longitudinal extension members 56 is also shown as beingprovided with a hinge recess 57 and a detent cavity 58. The hingerecesses 57 are configured to receive a hinge post 64 of the third hingearm 60 such that the third hinge arm 60 and the second hinge arm 50 arerotatable with respect to each other. Thus, in the configuration shown,the second hinge arm 50 is rotatable with respect to the third hinge arm60 about a rotational axis R2 that is coaxial with both the longitudinalaxis of the hinge post 64 and the center of the hinge recess 57. In theembodiment shown, the second hinge arm main body 52 is mounted to thedoor 12 such that the hinge recesses 57 are adjacent to the interiorsurface 12 a of the door 12 which prevents the hinge post 64 from beingremovable from the recesses 57 once the second hinge arm 50 is mountedto the door 12.

Each detent cavity 58 is configured to receive a corresponding detentprotrusion 66 provided on the third hinge arm 60. Although two detentcavities 58 and detent protrusions 66 are provided in the embodimentshown in the drawings, it should be noted that a single detent cavity 58and single corresponding detent protrusion 66 may be alternativelyprovided. In operation, the detent protrusions 66 and cavities 58 retainthe third hinge arm 60 in an engaged, rotation-resistant position withrespect to the second hinge arm 50. Once sufficient rotational pressureis applied to the hinge mechanism 10 via the door 12, the detentprotrusions 66 are forced to disengage from their corresponding cavities58, thereby allowing the second and third hinge arms 50, 60 become moreeasily rotatable with respect to each other.

It is noted that the length of the second hinge arm 50 can be selectedto match the height of the door 12. In the example shown, the secondhinge arm 50 is configured for a 1 RU height. However, the main body 52could be simply made longer to match a 2 RU height or other height.Alternatively, multiples of the main body 52 could be mounted to thedoor in an aligned position to achieve the desired height. In such aconfiguration, two main bodies 52 could be used to achieve a 2 RU heightin which the latch post 55 of the top arm main body 52 would be utilizedand the hinge recesses 57 and detent cavities 56 of the lower arm mainbody 52 would be utilized in the assembly. This approach would allow forthe same parts to be used regardless of the rack height which couldreduce tooling and manufacturing costs.

Referring to FIG. 13, the third hinge arm 60 is shown in greater detail.As shown, the third hinge arm 60 is provided with a main body 62. Thepreviously described opening 68 for the hinge post 48 of the first hingearm 40 is provided on a first extension portion 62 a of the main body 62while the previously described hinge post 65 and detent protrusions 66are provided on a second extension portion 62 b of the main body 62.

In one aspect, the third hinge arm 60 is provided with a dog-leg shapeor L-shape wherein the first extension portion 62 a extends generallyalong a third axis L3 and the second extension portion 62 b along afourth axis L4 that is at a non-zero angle to the third axis L3. Thefirst extension portion 62 a meets the second extension portion 62 b ata first angle a1. In the example shown, the first angle a1 is a rightangle or about 90 degrees. However, other non-zero angles may beutilized depending upon the specific physical configuration of the door12 and door hinge mechanism 10.

Referring back to FIGS. 1 and 7, it can be seen that the door 12 is inthe closed position such that the interior surface 12 a of the door isfacing the open front 30 of the chassis 14 and such that the latch post55 is engaged with the latch member 80. When the door 12 is in theclosed position, the door hinge mechanism 10 is oriented such that thefirst extension portion 62 a of the third hinge arm 60 is alignedgenerally parallel with the main body 42 of the first hinge arm 40 (i.e.axis L3 is generally parallel to axis L1). Additionally, the secondextension portion 62 b of the third hinge arm 60 is aligned generallyparallel with the main body 52 of the second hinge arm 50 (i.e. axis L2is generally parallel to axis L4) such that the detent protrusions 66are engaged with the cavities 58. Thus, the door hinge mechanism 10 isin the engaged position when the door 12 is in the closed position. Itis noted that the engaged position of the door hinge mechanism 10 allowsfor the weight of the door 12 to be largely supported from the hingeposts 48. This configuration reduces shear stresses on the latch members80 (and the latch posts 55) and serves to extend the useful service lifeof the latch members 80. It is also noted that the interior surface 12 aof the door 12 closes off the open side of the detent cavities 58 andprovides for a rotational stop against the second extension portion 62 bof the third hinge arm 60.

Referring to FIG. 8, it can be seen that the door 12 has been rotatedinto an intermediate open position, wherein the door hinge mechanism 10has been rotated about the first rotational axis R1 and the door hingemechanism 10 remains in the engaged position. As shown, the door 12 isin a generally horizontal position and the second extension portion 62 bof the third hinge arm 60 is generally parallel to the main body 42 ofthe first hinge portion 40 (i.e. axes L1 and L4 are generally parallel).However, the intermediate open position can include any position inwhich the door hinge mechanism 10 is in the engaged position and atleast some portion of the door 12 is above or in front of the bottomtray 16 a and/or related cable management feature 18 a. For example, thedoor 12 can be said to be in the intermediate position where the doorhas been rotated more than 90 degrees such that the top edge of the dooris resting on equipment 100 located below the chassis that extendsbeyond the open front 30 of the chassis 14.

Although the intermediate position allows for upper components withinthe chassis (e.g. upper trays 16 b, 16 c and their related cablemanagement features 18 b, 18 c) to be extended through the open front30, lower components (e.g. the bottom tray 16 a and its cable managementfeature 18 a) may be blocked from extending fully outward by the door12. Although the dog-leg or L-shape of the third hinge arm 60 isbeneficial for offsetting the position of the door 12 in the second openposition (discussed later), this shape also effectively raises theheight of the door 12 when in the intermediate position, resulting incomponents that may blocked from fully extending.

To ensure that all components within the chassis 14 can be extendedthrough the open front 30, even when the door 12 cannot be furtherrotated about rotational axis R1, the door 12 can be placed in a firstopen position. The first open position of the door 12 can be seen atFIGS. 2-5 and 9. The door 12 can be placed in the first open position bydisengaging the detent protrusions 66 from the detent cavities 58 byapplying a sufficient rotational force to the door 12 against the thirdhinge arm 60. Once the detent protrusions 66 and cavities 58 aredisengaged, the second hinge arm 50 can be easily rotated about thesecond rotational axis R2 with respect to the third hinge arm, therebyallowing the door 12 to reach a lowered generally horizontal position,as compared to when the door hinge assembly 10 is in the engagedposition. It is noted that rotation about the first rotational axis R1is still possible in the disengaged position which can be seen in thedifference in relative positions of the first and third hinge arms 40,60 between FIGS. 8 and 9. As can be seen at FIG. 9, the door 12 isgenerally aligned with the bottom of the chassis 14 or the top of theequipment 100 below the chassis 14.

As shown, the disengaged position of the hinge mechanism 10 includes thethird extension portion 62 b of the third hinge arm 60 being disposed ata non-zero angle with respect to the main body 52 of the second hingearm 50 (i.e. axes L2 and L4 are not parallel). It is noted that the mainbody 52 adjacent the slot opening 56 a functions to provides arotational stop against the second extension portion 62 of the thirdhinge arm 60 to define a limit on the degree to which the door 12 can berotated with respect to the third hinge arm 60. Accordingly, the secondand third hinge arms 50, 60 can be configured such that rotation betweenthem is stopped when the door 12 is held in a horizontal positionsufficiently below the open front 30.

As can be most easily seen at FIG. 8, the door 12 is in a generallyhorizontal position that is at least partially above the rotational axisR1 and hinge post 48 when the door hinge assembly 10 is in the engagedposition. In contrast, and as most easily seen at FIG. 9, the door 12can be maintained in a generally horizontal position that is lower thanthe rotational axis R1 and the hinge post 48 when the door hingeassembly 10 is in the disengaged position (i.e. the door 12 is below ahorizontal plane extending through the center of the hinge post 48).Accordingly, the first open position allows the door 12 to be loweredsuch that the door 12 does not block the open front 30 of the chassis 14without requiring the door 12 to be rotated past a horizontal position(which may not be possible if equipment 100 below the chassis wouldprevent such rotation). Referring to FIGS. 4 and 5, it can be seen thatthe first open position allows for the bottom tray 16 a and the relatedcable management feature 18 a to extend beyond the open front 30 of thechassis 14.

As shown at FIGS. 6 and 10, the door 12 can be further rotated into asecond open position. In the second open position, the door hingemechanism 10 is placed or maintained in the engaged position and thedoor 12 is rotated about the rotational axis R1 into a generallyvertical orientation that is about 180 degrees from the closed position.However, and as noted previously, the dog-leg or L-shape of the thirdhinge arm 60 allows the door 12 to be displaced forward such that it canoverlay the front face of equipment below the chassis 14, such asanother chassis 14. Such a configuration can be seen at FIG. 10 whereinthe open door 12 of the upper chassis 14 is in the second open positionwithout contact or interference from the door 12 of the chassis 14below. Such a configuration allows the hinge posts 48 to bear the loadof the door 12 without additional shear forces being imparted into thedoor hinge mechanism 10 by the equipment or chassis below.

Similar to the closed position, when the door 12 is in the second openposition position, the door hinge mechanism 10 is oriented such that thefirst extension portion 62 a of the third hinge arm 60 is alignedgenerally parallel with the main body 42 of the first hinge arm 40 (i.e.axis L3 is generally parallel to axis L1) and the second extensionportion 62 b of the third hinge arm 60 is aligned generally parallelwith the main body 52 of the second hinge arm 50 (i.e. axis L2 isgenerally parallel to axis L4) such that the detent protrusions 66 areengaged with the cavities 58. However, the first extension portion 62 a,when the door 12 is in the second open position, is oriented 180 degreeswith respect to the orientation of the first extension portion 62 a whenthe door 12 is in the closed position.

The door 12 and the door hinge mechanism 10 can be assembled such thatthe door is not removable from the chassis 14 without removing at leastone of the fasteners 70. This is most easily accomplished by mountingthe first hinge members 40 such that the hinge posts 48 are facing inopposite directions. For example, the first hinge members 40 can bemounted to the chassis 14 such that the second ends 48 b of the hingeposts 48 face each other in a direction towards the center of thechassis 14 or can be mounted to the chassis 14 such that the second ends48 b face away from each other in a direction away from the center forthe chassis 14. Fasteners can also be used on the hinge posts 48 toprevent removal of the door from the door hinge mechanisms 10 as well.Alternatively, the door hinge mechanism 10 and door 12 can be assembledsuch that the door 12 is removable from the chassis without having toremove one or both fasteners 70. This can be accomplished by mountingthe first hinge members 40 such that the second ends 48 b of the hingeposts 48 extend in the same direction which would allow the door to belaterally displaced along the hinge posts 48 for removal.

The hinge arms 40, 50, 60 of the door hinge mechanism 10 may be made ofmany different materials, for example, metal materials and plastics.Further, the arms may be produced by a variety of processes, forexample, molding, casting, machining, and three-dimensional printing.

Although in the foregoing description, terms such as “top,” “bottom,”“front,” “back,” “right,” “left,” “upper,” and “lower” were used forease of description and illustration, no restriction is intended by suchuse of the terms. The telecommunications devices described herein can beused in any orientation, depending upon the desired application.

Having described the preferred aspects and embodiments of the presentdisclosure, modifications and equivalents of the disclosed concepts mayreadily occur to one skilled in the art. However, it is intended thatsuch modifications and equivalents be included within the scope of theclaims which are appended hereto.

1. A door hinge mechanism for pivotally coupling a door to atelecommunications chassis, the hinge mechanism comprising: a. a firsthinge arm configured to be non-rotatably affixed to thetelecommunications chassis; b. a second hinge arm configured to benon-rotatably affixed to the door; and c. a third hinge arm having afirst extension portion pivotally attached to the first hinge arm andhaving a second extension portion pivotally attached to the second hingearm, the first extension portion meeting the second extension portion atan angle to form a dog-leg shaped hinge arm.
 2. The door hinge mechanismof claim 1, wherein the third hinge arm is rotatable with respect to thefirst hinge arm about a first rotational axis and is rotatable withrespect to the second hinge arm about a second rotational axis.
 3. Thedoor hinge mechanism of claim 1, wherein the door hinge mechanismfurther includes a detent structure to resist rotation between the thirdhinge arm and the second hinge arm about the second rotational axis. 4.The door hinge mechanism of claim 3, wherein the detent structureincludes a detent protrusion located on one of the first and secondhinge arms and a detent cavity located on the other of the first andsecond hinge arms.
 5. The door hinge mechanism of claim 4, wherein thedoor hinge mechanism is positionable into an engaged position in whichthe detent protrusion engages with the detent cavity, and wherein thedoor hinge mechanism is positionable into a disengaged position in whichthe detent protrusion is disengaged from the detent cavity.
 6. The doorhinge mechanism of claim 1, wherein the second hinge member furtherincludes a latch post configured to engage with a latch recess of thechassis to releasably retain the door in the closed position.
 7. Thedoor hinge mechanism of claim 1, wherein first hinge arm is pivotallyattached to the third hinge arm by a hinge post located on the firsthinge arm that is received by an opening extending through the thirdhinge arm.
 8. The door hinge mechanism of claim 7, wherein the secondhinge arm is pivotally attached to the third hinge arm by a second hingepost located on the second hinge arm that is received by a recessdefined in the second hinge arm.
 9. The door hinge mechanism of claim 8,wherein the second hinge arm further includes a slot opening into whichthe third hinge arm is received.
 10. A telecommunications systemcomprising: a. a telecommunications chassis defining an open front face;b. a door pivotally attached to the telecommunications chassis via ahinge mechanism, the hinge mechanism comprising: i. a first hinge armaffixed to the telecommunications chassis; ii. a second hinge armaffixed to the door; and iii. a third hinge arm having a first extensionportion pivotally attached to the first hinge arm and having a secondextension portion pivotally attached to the second hinge arm, the firstextension portion meeting the second extension portion at an angle toform a dog-leg shaped hinge arm.
 11. The telecommunications system ofclaim 10, wherein the third hinge arm is rotatable with respect to thefirst hinge arm about a first rotational axis and is rotatable withrespect to the second hinge arm about a second rotational axis.
 12. Thetelecommunications system of claim 10, wherein the door hinge mechanismfurther includes a detent structure to resist rotation between the thirdhinge arm and the second hinge arm about the second rotational axis. 13.The telecommunications system of claim 12, wherein the detent structureincludes a detent protrusion located on one of the first and secondhinge arms and a detent cavity located on the other of the first andsecond hinge arms.
 14. The telecommunications system of claim 13,wherein the door hinge mechanism is positionable into an engagedposition in which the detent protrusion engages with the detent cavity,and wherein the door hinge mechanism is positionable into a disengagedposition in which the detent protrusion is disengaged from the detentcavity.
 15. The telecommunications system of claim 10, wherein thesecond hinge member further includes a latch post configured to engagewith a latch recess of the chassis to releasably retain the door in theclosed position.
 16. The telecommunications system of claim 10, whereinfirst hinge arm is pivotally attached to the third hinge arm by a hingepost located on the first hinge arm that is received by an openingextending through the third hinge arm.
 17. The telecommunications systemof claim 16, wherein the second hinge arm is pivotally attached to thethird hinge arm by a second hinge post located on the second hinge armthat is received by a recess defined in the second hinge arm.
 18. Thetelecommunications system of claim 17, wherein the second hinge armfurther includes a slot opening into which the third hinge arm isreceived.
 19. A telecommunications system comprising: a. atelecommunications chassis having an open front extending along a firstplane; b. a hinge mechanism pivotally attached to the telecommunicationschassis, the hinge mechanism being rotatable with respect to thetelecommunications chassis about a first rotational axis; c. a doorpivotally attached to the hinge mechanism, the door being rotatable withrespect to the hinge mechanism about a second rotational axis, the doorbeing positionable between: i. a closed position in which the door isdisposed in a generally vertical position to at least partially coverthe open front of the chassis, wherein the door is located above ahorizontal plane extending through the first rotational axis and behinda vertical plane extending through the first rotational axis; and ii. afirst open position in which the door is disposed in a generallyhorizontal position, wherein the door is at least partially below thehorizontal plane extending through the first rotational axis.
 20. Thetelecommunications system of claim 2, wherein: a. The door is furtherpositionable to a second open position in which the door is disposed ina generally vertical position and rotated from the closed position aboutthe first rotational axis by about 180 degrees, wherein the door isdisposed forward of the vertical plane extending through the firstrotational axis.